The Ocean Food Web: I

Gulf of Maine Expedition

contributed scientific chronicles from the Harbor Branch Oceanographic Institute At-Sea

The Gulf of Maine is among the most productive marine habitats in the world. The basis for this large and productive fishery is the photosynthetic phytoplankton that constitute the base of the coastal marine food web. The open waters of the oceans and its enclosed seas – the pelagic realm – cover 70% of earth’s surface and are inhabited by an astronomical number of minute algal cells (phytoplankton) that grow suspended in the sunlit surface layer. Their photosynthesis provides the food (organic matter) that sustains the bacteria, the unicellular protozoa and the minute animals (mostly midge-sized crustacea) of the zooplankton. These in turn are food of the higher levels of the marine food web (fish and whales). The bacteria, protozoa and zooplankton break down organic matter thereby returning nutrients to the phytoplankton. The activity of individual organisms through the seasons adds up to cycling of essential elements, in particular carbon, nitrogen, phosphorous and silica, that extend from millimetre to global scales. The study of these cycles is called biogeochemistry. Evidence is mounting that the biogeochemical cycles run by the pelagic ecosystems are essential cog-wheels within the complex machinery regulating earth’s climate.

From September 9 to September 27, 2003, Harbor Branch Oceanographic Institute (HBOI) research scientist, Dr. Marsh Youngbluth, and a team of collaborators continued part of their three-year, multi-seasonal investigation into the ecological effects of predation by gelatinous zooplankton in the Gulf of Maine. The research was conducted at three sites: at Wilkinson Basin in the Gulf of Maine, in the shallow shelf/slope water of Georges Bank and in the deep water of Oceanographer Canyon. The Gulf of Maine is a roughly rectangular, partly enclosed sea occurring along northeastern North America, from Cape Cod, Massachusetts, north to the northern Bay of Fundy, and east to Cape Sable, Nova Scotia. The Gulf is bounded along its Atlantic margin by Georges Bank and Browns Bank, which are large, shallow shoals that greatly reduce water exchange with the open ocean. The entire Gulf occupies an area of approximately 91,000 square km (36,000 square miles). A series of 21 basins lie within the Gulf of Maine. The deepest (300-400 m) of these include Georges, Wilkinson and Jordan basins.

Once water has entered the Gulf, it is directed to the northeast toward Nova Scotia and the Bay of Fundy by the rotation of the Earth. A single revolution around the entire Gulf takes about three months. As restricted as the communication between the Gulf of Maine and the open ocean is now, it was even more isolated in the very recent geological past. The last of the Great Glaciers that scoured the Gulf’s basins began to retreat some 13,000 years ago. Once freed from the tremendous weight of an ice sheet more than a mile thick, the terrestrial and submarine land rebounded and the sea withdrew to a level that was about 60 m less than the current sea level. At this point (around 11,000 years ago), Georges and Browns banks were emergent land masses. Water entry into Gulf was limited to the tidal flow through the narrow Northeast Channel. The tidal range today can exceed 15 m (45 feet) between low and high tide.

The research was accomplished using the Johnson Sea-Link (JSL) manned submersible, which allows these scientists to gain a better understanding of the distribution and behavior of pelagic animals that are too delicate to be adequately studied with traditional approaches. This expedition was made possible through a grant from the Biological Oceanography Program of the National Science Foundation (NSF) with additional support from Harbor Branch

 


MISSION DISPATCH 1 Tuesday, September 9, 2003
Location: Wilkinson Basin (42° 28’N, 69° 42’W)

Dispatch by Harry Breidahl – Marine Education Society of Australasia [MESA]

After sailing from its home base in Fort Pierce, Florida the R/V Seward Johnson berthed at the NOAA Pier in Woods Hole, Massachusetts on Sunday September 7th. The ships’ crew, some of the science party, technical support group and the submersible crew were on board for the long and rather lumpy transit north. The remainder of the ships’ compliment flew into Boston on Monday 8th then drove south to join their shipmates.

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Maine underwater survey
Credit: USGS, HBOI/At-Sea.org

The new arrivals made for a complement of around 30 on board for the Fall 2003 Maine Event. As is the case with most HBOI research cruises, the scientific party had flown in from far and wide. Nations represented include Finland, Norway, Spain and Australia. Some of the marine scientists have participated on previous Maine Event cruises and bring many years of oceanographic experience to the program. Other important components of the science group are the graduate and undergraduate university students who will conduct thesis projects and broaden at-sea skills. The main research tools are the manned submersible JOHNSON SEA-LINK II (JSL) and a multi-net system called MOCNESS.

Early plans had the R/V Seward Johnson steaming out to the deep water canyons south of Georges Bank on the evening of Monday 8th. However, the influence of storms to the east and south revised this schedule. We slipped away from the dock at 7.30 am on Tuesday and sailed for the relatively calm, 300-m deep site in Wilkinson Basin. A few days of JSL sub dives and MOCNESS tows are planned at this location, during the first segment of this 19-day cruise.

As we traveled through the Cape Cod Canal, it was fascinating to see the science party and sub crew engaging in the usual process of outfitting the JSL with detritus samplers, ‘critter gitter’ buckets, scaling lasers and environmental sensors. This passage also provided a brief period of calm water before those of us who needed a little time to find our sea-legs headed below as we entered a choppy sea.

Once reaching Wilkinson Basin, the Fall 2003 Maine Event research program began with a JSL sub dive at 8.30 pm. This plunge was number 3436 for Johnson-Sea-Link II. It is amazing to think that this versatile submersible is approaching its 3500th dive. Although a few things didn’t happen as to plan, the initial dive was regarded as a successful shake-down. Siphonophore Nanomia cara colonies were scarce and appeared only at 20 m near the base of the thermocline. However, other gelatinous zooplankton called ctenophores (Bolinopsis infundibulum and Beroe cucumis) were common throughout the water column. A few of these ctenophores were collected to begin tests of micro opodes, special optical devices that will be used to measure respiration rates. Copepods were also obtained for University of Rhode Island graduate student Whitley Saumweber to begin his study of the respiration rates of the resting stage of the copepod Calanus finmarchicus. More detail about these studies of metabolism will appear in subsequent dispatches.

MISSION DISPATCH 2 Wednesday, September 10, 2003
Location: Georges Basin (42° 18’N, 67° 30’W)

Dispatch by Harry Breidahl – Marine Education Society of Australasia [MESA]

After a single JSL dive to 860 feet (260 meters) and two MOCNESS net tows at Wilkinson Basin, the R/V SEWARD JOHNSON headed east toward Georges Basin in anticipation of benign weather. We left Wilkinson Basin at 10.30 am and arrived at our second survey site just before 7 pm. Under clear night skies and a brilliant full moon, JOHNSON SEA-LINK II dive 3437 splashed into the water around 8.30 pm and returned to the aft deck just before midnight. Colonies of Nanomia cara were sufficiently numerous to at this site to allow detailed investigations of their feeding behavior.

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Maine nanomiacara
Credit: HBOI/At-Sea.org

The scientific party on board numbers 12. As the focus of research for The Maine Event is the siphonophore Nanomia cara we have three ‘gelatinous gurus’ leading the way. They are mission leader Dr Marsh Youngbluth from HBOI, Dr Per Flood from Bathybiologica, Bergen, Norway and Dr Francesc Pages from the Institute of Marine Science in Barcelona, Spain. Three graduate students on board conduct their own research programs. They are Aino Hosia, originally from Finland but studying at the University of Bergen in Norway, Whitley Saumweber from the University of Rhode Island and Brian Ortman from the University of New Hampshire.

Dr Chuck Jacoby from the University of Florida leads a small team that provides support for all of the scientific programs on board. Included in this team are Helen Mayoral, a research assistant at HBOI, Nicole Shach, an undergraduate student at the University of Florida and Brennan Phillips, an undergraduate engineering student at the University of Rhode Island. The two remaining members of the scientific party are Brian Cousin and myself. Brian is a video production specialist at HBOI and is aboard to document the research activities of scientists on this cruise. As an educator and author, my role is to write these web dispatches and to gather information relevant to the development of ocean exploration programs for schools.

As this voyage progresses we will highlight the scientific and technological efforts of the people on the R/V SEWARD JOHNSON. For today’s dispatch we look at Whitley Saumweber’s work. Whitley is currently in the fifth year of a project studying the population dynamics of the resting stage of the copepod Calanus finmarchicus (the main food source for Nanomia). On this cruise he is measuring the respiration rates of the resting stage of C. finmarchicus in order to understand how this torpid portion of the population is able to survive.

Whitley uses live individuals collected by samplers attached to the JSL or sieved into the nets of a MOCNESS tow. Like all living animals, these tiny copepods need oxygen to survive. They extract this oxygen from the sea water. The more active a copepod is, the more oxygen it will use. For each test Whitley carefully selects a healthy number (30) of copepods places them into a known volume of water (300 ml) for 24 or 48 hours. During this period of incubation the copepods are kept in a cool, dark room that mimics the chilly temperatures in their deep-sea habitat. By comparing the amount of oxygen in the water at the start and the end of a set time, he can calculate the amount of oxygen consumed by the copepods.

MISSION DISPATCH 3 Friday, September 12, 2003
Location: Georges Basin (42° 18’N, 67° 30’W)

Dispatch by Harry Breidahl – Marine Education Society of Australasia [MESA]

Today is our third day at Georges Basin and the weather is holding well – for the present. The crew of the R/V Seward Johnson is monitoring the progress of hurricane Isabel to our southeast. This huge storm could make our lives uncomfortable, especially if the turbulence moves toward the Gulf of Maine. Hurricane Isabel is a timely reminder of how much oceanic research is influenced by events beyond human control.

By midnight Friday the scientific party had completed five successful dives in JOHNSON SEA-LINK II (JSL), two MOCNESS net tows and one CTD cast at this location. Colonies of Nanomia cara are abundant at Georges Basin, and distributed in a narrow 30-meter (100-foot) thick layer beginning at 220 meters (720 feet). Unfortunately, the failure of a pump aboard the JSL II has curtailed the collection of Nanomia for stomach content analysis. The problem is minor and the sub crew will be able to solve it before the next dive tomorrow morning.

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Maine submersible
Credit: HBOI/At-Sea.org

While this aspect of The Maine Event 2003 program is currently limited, other segments are firing along nicely. Per Flood has been comparing and documenting morphological differences among midwater appendicularians collected during last year’s Maine Event. Many of these fragile animals are undescribed species and we’ll be searching for more specimens on this cruise. The work of graduate students Aino Hosia, Whitley Saumweber and Brian Ortman is progressing well. Much of Aino’s time is spent monitoring recently developed optical technology that uses fluorescence quenching to log oxygen consumption rates of freshly captured colonies. Nanomia is maintained in one of two cold rooms on the R/V Seward Johnson for these experiments. This project provides an opportunity for comparison with Whit’s study of copepod respiration rates. Brian is collecting and flash-freezing a range of gelatinous fauna for genetic studies. The DNA content of these samples will be investigated with special instruments when he returns to laboratory facilities on land.

Over the past few days, all three graduate students have taken their first dive into the deep-sea aboard JSL II. This versatile submersible has two crew compartments. The front chamber is an acrylic sphere that provides almost 2700 of view for a scientist. The aft chamber, which is made of aluminum, has room (just) for a second member of the sub crew and a second scientist. There are two small viewing ports on either side of this compartment. The opportunity to see planktonic animals behave in their natural habitat is, in a commonly expressed word, "awesome."

The youngest person on board the R/V Seward Johnson, Nicole Shach made her initial dive on September 12, her 22nd birthday. What better treat (at least for a budding marine biologist) than a up-close visit to the briny realm of Nanomia cara and its gelatinous cousins. This JSL II dive was number 3440. Scientist Marsh Youngbluth shared the front compartment with sub-pilot Dan Boggess and sub-pilot Tim Askew Jr dove in the aft compartment with Nicole. Following her dive, Nicole donned bright orange overalls and helped process colonies for analyses of the prey they consumed.

MISSION DISPATCH 4 Saturday, September 13, 2003
Location: Georges Basin (42° 18’N, 67° 30’W)

Dispatch by Harry Breidahl – Marine Education Society of Australasia [MESA]

Last night gelatinous animals had sudden and unexpected impact on daily life aboard the R/V Seward Johnson. For a day or so, the ships engineers have been struggling to clean the seawater intakes for the vessel. That’s where the gelatinous animals come in – literally. Seawater is used to cool the engines and is also utilized for the desalination system that provides our freshwater. Pipes that bring this seawater into the vessel have filters that are currently being clogged by masses of surface-dwelling gelatinous zooplankton.

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Maine apolemia
Credit: HBOI/At-Sea.org

The first hint of a plankton bloom surprised us a couple nights ago when Whitley Saumweber collected seawater in a bucket. Whit needed the water for his research on copepod respiration. After first notifying the bridge and donning a life jacket (both critical safety precautions) he lowered a bucket over the gunnel. What he caught with the water was most interesting – a few mysid shrimps and a lot of little bluish creatures called salps. Not a great deal of attention was given to this discovery at the time because the sunlit surface waters of the Gulf of Maine are normally rich in planktonic life. That all changed last night when Assistant Engineer Erik Bergendahl came into the dry laboratory to show us filters clogged with blue gelatinous goop. Per Flood and Francesc Pages identified this slimy material as the remains of Thalia democratica, the same salp that had been collected by Whit. The fact that these creatures are fouling the seawater inlet filters means that we are suffering a "salp induced drought" on board and the use of fresh water has been restricted.

Despite the water rationing, everyone is busy aboard R/V Seward Johnson. Early this morning a couple vertical plankton tows literally brimmed with plankton, especially the prolific salps. Various creatures were scooped from the soupy collection to be examined, photographed and eventually preserved in one way or another for future, more detailed studies of their genetic makeup or chemical composition. The sub crew rebuilt one of the critter gitter pumps, which allowed us to collect dozens of Nanomia colonies during day and night JOHNSON SEA-LINK II (JSL) excursions into the depths of Georges Basin (dives 3442 and 3443). Based on in situ observations by scientist Francesc Pages and sub pilot Craig Caddigan sitting in the sphere and undergraduate Brennan Phillips and sub-crew Jim Pierce in the aft chamber, it was clear that a portion of the Nanomia cara population migrated nearly 200 m upward during the night. Why? Our preliminary examinations suggest they move into shallower waters to dine on small copepods. The last activity at this location was a CTD cast at midnight to obtain water samplers for fatty acid analyses.

We’ve spent only four days at this location and there is more to learn but the seas are calm and predicted to remain benign for a few days. So, we’ve decided to steam to the southern edge of Georges Bank to gather comparative data on colonies that live in the deep water canyons. Hopefully, we will be able to operate there for a few days before the impending storms prevent submersible dives and over-the-side operations. In anticipation of our transit, all laboratory equipment and other odds and sods have been strapped down or stowed away. We will steam for the next 16 hours. Our expectation for tomorrow is a 2,900 foot (900 meter) plunge into Oceanographer Canyon and the chance to observe and collect a much different, more diverse community of plankton.

MISSION DISPATCH 5 Sunday, September 14, 2003
Location: Oceanographer Canyon (40° 17’N, 68° 7’W)

Dispatch by Harry Breidahl – Marine Education Society of Australasia [MESA]

The 16 hour transit from Georges Basin to Oceanographer Canyon (our third area of operation) began early this morning. Along the way the weather was fine and low swells made for a smooth passage. After almost a week at sea the transit provided us with a brief break in the hectic daily shipboard schedule. Because time at sea is limited, scientists on board must pack as much as they can into every day. In other words, all of the scientific party must adjust their sleep patterns to fit a 24 hour program of field work (sub diving, MOCNESS net towing, CTD deploying) and laboratory work (sorting, preserving, counting, photographing, measuring, and monitoring with stereo microscopes, video/still cameras, and data-logging computers). Coming from Australia, the added time difference of 14 hours has made this adjustment especially tough for me, it is hard to tell night from day.

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Maine ptychogena lactea
Credit: HBOI/At-Sea.org

R/V Seward Johnson reached Oceanographer Canyon at 4.15 pm. Clear oceanic blue waters surrounded us and we look forward to exploring a water column three times deeper than Georges Basin, down to 980 meters. At Georges Basin, we had been drifting in a bloom of surface dwelling salp aggregates. Here at Oceanographer Canyon, we were introduced to a beautiful medusa known as Pelagia noctiluca when graduate student Brian Ortman netted a specimen and brought it into the dry lab in a bucket. That night we were surrounded by these beautiful creatures but thankfully they were too large to clog the vessel’s saltwater intakes and drifted peacefully by.

The R/V Seward Johnson has several laboratories on-board. Some are permanent while others are temporary, specialized labs housed in shipping containers fixed (very firmly) to the vessel’s decks. One of the permanent labs is called the wet lab because anything that requires working with seawater is conducted there. On this voyage a peculiar piece of equipment in the wet lab is the circular, upright aquarium, called a plankton kreisel. It has been used to take photographs of Pelagia noctiluca and will be utilized again for imaging other gelatinous zooplankton from tonight’s dive.

JOHNSON SEA-LINK II (JSL) dive 3444 was a night dive and our first at a deep canyon site for this year’s Maine Event. Marsh Youngbluth and sub pilot Tim Askew Jr. were in the forward sphere, while the aft compartment was occupied by research assistant Helen Mayoral and sub crew Alan Fuller. The dive began at 8.30 pm and reached a depth of 2,700 feet (820 meters). Three and a half hours later (at midnight), the well rehearsed routine of recovering the sub was witnessed by the usual collection of expectant scientists.

The return of JSL II to the aft deck is always a much anticipated event and on this occasion the waiting scientists were in for a treat. In addition to the usual cargo of Nanomia cara colonies, Marsh and Tim captured a deep-sea cranchid squid and a midwater cirrate octopus (Stauroteuthis syrtensis) at 800 m. The 20 cm long squid had two large and darkly pigmented eyes but the most striking feature was the animal’s ability to be almost transparent one moment and highly freckled in the next. This feat was accomplished by a rapid concentration and dispersal of pigment in special cells called chromatophores. The 30 cm octopus was a vivid reddish-orange color, had a membranous web of skin between its tentacles and possessed two small flipper fins just behind the eyes (hence the common name of dumbo octopus). This animal is one of only two octopus species in the world that are known to bioluminesce. The suckers along the arms have evolved into light-emitting organs that glow blue-green in the perpetual darkness of its habitat.

MISSION DISPATCH 6 Monday, September 15, 2003
Location: Oceanographer Canyon (40° 17’N, 68° 07’W)

Dispatch by Harry Breidahl – Marine Education Society of Australasia [MESA]

Our second day at Oceanographer Canyon and expectations of productive dives are high. At present the seas are calm and the air is warm but the weather forecast does not sound promising. Hurricane Isabel is approaching from the southeast and we anticipate that our time at this location may soon be curtailed.

The submersible dove at 1 pm with scientist Chuck Jacoby and sub pilot Dan Boggess in the acrylic sphere and graduate student Aino Hosia joined by sub crew Jim Pierce in the aft aluminum chamber. As with the sub dive last night, dive 3445 for JSL II reached 2,700 feet (820 meters) in depth. The results were equally valuable, providing plenty of living animals for the experiments on board.

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Maine stauro
Credit: HBOI/At-Sea.org

The next dive is the one that I have been waiting for. It is my turn to squeeze into the small aft chamber and travel to the bottom of Oceanographer Canyon. This dive was special for me because I had brought a collection of styrofoam cups that Australian school children had decorated. Taking foam cups down on the outside of a submersible is a simple, but effective way of demonstrating how pressure increases with depth. There are many ways to measure pressure but the most simple way is to say the pressure at sea level is 1 atmosphere (1 atmosphere = 1 kg/sq cm or 14 lbs/sq inch). For every 10 meters (33 feet) a sub descends, 1 atmosphere of pressure is added by the mass of water above it. At 10 m the pressure is 2 atmospheres, at 20 m it is 3 atmospheres and so on as we travel down. By 800 m the pressure is 81 atmospheres – that is 80 times greater that the pressure at the surface or 81 kg/sq cm.

This increase in pressure is why submersibles, such as JOHNSON SEA-LINK II (JSL) , need to be so strong. The occupants inside the two chambers are safe because the walls are thick enough to resist the incredible pressure. However, anything on the outside of these two chambers is subject to the increase of pressure with depth. With our cups, the pressure is enough to crush the air bubbles inside the foam. This action shrinks the cups to tiny versions (roughly 4 times smaller) of the original cups.

JSL II dive 3446 was a great thrill for me. I dove in the other JOHNSON-SEA-LINK (JSL I) last year but managed to forget how small the aft chamber really is. No matter how cramped the chamber, the whole experience of plunging to 800 m below the waves into a dark, cold, hyperbaric world is an experience never to be forgotten. There is so much life down there and most of it is rarely seen and quite bizarre.

As soon as we returned to the surface and transported the midwater animal cargo (another collection of siphonophores and other gelatinous creatures called ctenophores and medusae) into the wet lab we checked the condition of the cups. The colorful patterns that many of the children back home in Australia had written or drawn (in waterproof ink of course) on the cups had shrank along with the cups themselves. The colored sections seemed to shrink less and create all manner of beautiful patterns on the cups. The plan is for me to take the cups back to Australia and send them to the children who created them.

By the end of the day it became clear we needed to move closer to shore. The forecast of strong winds and high waves means we will not be able to launch the submersible or the traditional sampler gear (nets and bottles). So, we have to leave this canyon site as soon as we secure (tie-down) all the equipment. The current plan is to dive for a day at Wilkinson Basin and then steam into the safe harbor at Gloucester, Massachusetts.

MISSION DISPATCH 7 Tuesday, September 16, 2003
Location: Wilkinson Basin (42° 28’N, 69° 42’W)

Dispatch by Harry Breidahl – Marine Education Society of Australasia [MESA]

Our time at Oceanographer Canyon was unfortunately cut short by the impending arrival of 14 foot (4 meter) swells headed our way, courtesy of Hurricane Isabel. Immediately following last night’s dive (JSL II dive 3446), gear was stowed away and we headed back to Wilkinson Basin. As this site is closer to shore and more sheltered, the science party had an opportunity to work one more day before the transit to a safe harbor.

Two dives were completed today. JOHNSON SEA-LINK II (JSL) dive 3447 was hoisted from the aft deck at 2.30 pm and returned at 5.30 pm. Dive 3448 hit the water at 9.00 pm and landed on the aft deck at 11.45 pm. Although no colonies of Nanomia cara were seen on either dive, the undersea excursions were highlighted by collections of a few small and exquisitely delicate medusae – Ptychogena lactea and an unknown tiarannid (if you go back to Dispatch 5 you will find out that a medusa is what scientists call a jellyfish). Also collected were several ctenophores (including Bolinopsis infundibulum, Euplokamis dunlapae and Beroe cucumis). The swimming and feeding behaviors of most of these species were observed, oxygen consumption was measured, and tissues were preserved for molecular sequencing.

The fact that fragile midwater organisms were brought to the surface in prime condition clearly highlights the collection capabilities of the JSL submersibles and the proficiency of their pilots, in this case Craig Caddigan. The clear acrylic sphere of a JSL sub provides an uninterrupted forward view for a scientist sitting beside a sub pilot who controls the nine electric thrusters that maneuver the sub. A skillful sub pilot can approach and capture even the most delicate gelatinous midwater creature, in either the 24 "critter gitter" canisters or in the 8 "detritus" samplers. While the critter gitter package is relatively easy to maintain, the detritus samplers need constant maintenance and a special kind of subtle, but firm tinkering. That is one of the tasks at which Chuck Jacoby excels and, on this cruise, so does undergraduate marine engineering student Brennan Phillips. These two guys are absolute masters at keeping the temperamental detritus samplers functioning properly.

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Maine tiarannid
Credit: HBOI/At-Sea.org

The hour or so before every JSL dive is always a hectic period of checking the all the critical control functions and outfitting the sub with sampling chambers. Last minute adjustments are often needed before the sub is hoisted into the sea on schedule. Then a period of three and a half hours elapses while the sub is diving. During this time some of the science party continue to work in the shipboard laboratories on various projects. Others go below and roll into their bunks to catch an hour or two of sleep. Activities continue 24 hours a day and so it is not uncommon to see scientists taking a brief nap in one of the labs or elsewhere on board.

The R/V Seward Johnson is underway now heading for Gloucester, Massachusetts. If all goes to plan we will return to the sea on Saturday and continue The Main Event 2003 research program. New mission dispatches will resume at that time.

MISSION DISPATCH 8 Friday, September 19, 2003
Location: Gloucester, Massachusetts (42° 37’N, 70° 39’W)

Dispatch by Harry Breidahl – Marine Education Society of Australasia [MESA]

Hurricane Isabel has forced a brief but frustrating curtailment of The Maine Event for the 2003 season. The last three days in the port of Gloucester, Massachusetts have been used in different ways by those on board the R/V Seward Johnson . Two of the students, namely Brennan Phillips and Brian Ortman, took the long trip back to class and to consult with academic supervisors. Graduate student Whitley Saumweber remained on board to review his metabolic data on the resting stage of the copepod Calanus finmarchicus . Doctoral candidate Aino Hosia suspended measurements of oxygen consumption by Nanomia cara because the supply of living colonies can only be obtained while we are at sea. Marsh Youngbluth, Chuck Jacoby, Per Flood and Francesc Pages stayed aboard and examined the records, photographs and specimens that have been obtained on this and previous Maine Event research cruises. Marsh and Chuck also moved the plankton kreisel from the wet lab to one of the temperature-controlled rooms (a lab chilled to 70 C – the ambient temperature for Nanomia cara).

All these activities highlight the fact that for research scientists fieldwork is only the tip of the iceberg. For every day spent at sea, in our case plunging thousands of feet below the waves in a submersible, many weeks and often months are spent in both preparation and follow-up work.

HBOI video production specialist Brian Cousin and I explored Gloucester and, in Brian’s case, documented this historic port on video. Being a newcomer to this part of the world, I was curious about the history of the New England coastline. In particular, the Fisherman’s Monument on the foreshore indicated the strong bonds between this town and the sea. According to the monument, Gloucester was first settled by Europeans in 1623 "to harvest the bounty of the sea". The people that came to this New England coast did so to exploit the rich fish stocks that occur between Gloucester and Newfoundland. But harvesting the production of the sea is by no means a risk-free pursuit. Since those early days of 1623 and the establishment of Gloucester as America’s greatest fishing port, a total of 5,368 local fishermen have perished at sea – "overtaken by howling winds and mountainous seas". In 1862 a single storm claimed 15 schooners and took the lives of 120 men. In the year 2003 satellites and other modern weather forecasting techniques provide warning of approaching storms well in advance. Such predictions were not available to earlier generations of seafarers. It was a hurricane that brought us to the port of Gloucester, the town made famous by the Perfect Storm and by the ocean’s bounty.

Early tomorrow morning we will go to sea again to resume investigations of a different aspect of the ocean’s production, the rich diversity of gelatinous life in the basins of the Gulf of Maine and in the deep water canyons that indent the southern edge of Georges Bank.